Jenson Button said that the new McLaren upgrade was "a definite step forward" but was frustrated in his attempts to get the potential out of the car.

Like Red Bull, McLaren brought a major upgrade to Barcelona for the final two days of pre-season testing, with a revised front end and floor part of the package. However, Button's running was limited by a hydraulics problem in the morning and rain in the afternoon, leaving him frustrated at the end of a day in which he only completed 44 laps.

"[The upgrade} worked out well for the laps that I actually ran!" Button said. "Today was the day that we put the new updates on the car, and immediately when we put it on the car felt much better. There were some areas that we were lacking in with the car but we knew would become better when we put the updates on.

"I did two runs this morning, both runs were very difficult because we had issues with the hydraulics but we wanted to get some running in to collect some data for the new package. Then we had two hours plus of downtime before lunch. So we lost a lot of the day, especially the good part of the day when it's good temperature and no wind - we missed all of that - so after lunch we went out and we did some short runs, basically comparing tyres.

"The car felt pretty good but the problem was we didn't want to change the setup too much because we were comparing tyres, so we were just about to get in to the setup work and then it started raining. We didn't progress with our package today due to a bit of bad luck with the weather and obviously our issue this morning."

Despite the frustrations, Button was buoyed by the improvement in performance shown by the new upgrade, and said he hoped team-mate Lewis Hamilton could extract its potential.

"It's a definite step forward and I'm very happy with what we've achieved with this package, great that we got it here today, but we weren't able to progress with it and get a perfect setup. Hopefully tomorrow Lewis will get a nice clean day; good running and we can progress with it because there's still more to come with it. But the feeling is positive, I'm happy with the direction we've taken with it."